Transport infrastructures for the Grand Paris Express
After Boulogne, Villejuif Louis-Aragon and Créteil l’Echat, SADE is continuing its work!

Line 15
Line 15 is an underground metro line (75km) which runs throughout the Greater Paris metropolitan area and forms an outer ‘ring road’. Its aim is to decongest the public transport networks and provide an efficient service to the departments surrounding Paris, by forming a regional network alongside the existing transport services. It thus offers the possibility to travel from suburb to suburb without having to transit via central Paris.
This ‘ring road’ consists of three sections, including Line 15 South, which links 16 stations from Pont de Sèvres to Noisy-Champs in 35 minutes.
This 33km line will serve more than 22 municipalities and is the first to be commissioned. 300,000 journeys are expected per day, with a capacity of 1000 passengers per train.
T3A: SADE Special Works on the job
On behalf of the Société du Grand Paris and as part of the Horizon consortium (with Bouygues acting as agent), SADE is responsible for the section between Pont de Sèvres and Clamart stations.
It will carry out the civil engineering works for 3 ancillary structures, ventilation shafts and fire service access points:
- Boulogne-Billancourt (P12),
- Issy-les-Moulineaux, Place de la Résistance (P10),
- Issy-les-Moulineaux, Parc Henri Barbusse (P09).
Such facilities have been made compulsory every 800m since the Mont Blanc tunnel fire of 1999.
They are designed to protect and evacuate users of the future metro in the event of an incident or serious fire in the railway tunnel.
These diaphragm-wall shafts measure 10m in diameter. Works are carried out at depths of between 45m and 59m.
13 months of works are scheduled, for delivery in October 2023.